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Entry  Wed Nov 23 17:48:16 2016, rana, koji, Update, IOO, How bad is the McWFS? 
    Reply  Sat Nov 26 19:16:28 2016, Koji, Update, IOO, IMC WFS Demod board measurement & analysis WFS_demod_response.pdfWFS_demod_noise.pdfWFS_demod_noise_plan.pdfScreen_shot_2011-07-01_at_11.13.01_AM.png
       Reply  Tue Nov 29 17:45:06 2016, Koji, Update, IOO, IMC WFS Demod board measurement & analysis demod.pdfWFS_demod_response.pdfWFS_demod_noise.pdf
          Reply  Tue Nov 29 18:35:32 2016, rana, Update, IOO, IMC WFS Demod board measurement & analysis 
             Reply  Fri Dec 2 18:02:37 2016, Koji, Update, IOO, IMC WFS Demod board measurement & analysis WFS_demod_noise_orig.pdfWFS_demod_noise_mod.pdf
                Reply  Sat Dec 3 13:27:35 2016, Koji, Update, IOO, IMC WFS Demod board measurement & analysis WFS_demod_noise.pdfdemod.pdf
                   Reply  Tue Dec 6 13:37:02 2016, Koji, Update, IOO, IMC WFS Demod board measurement & analysis demod.pdfWFS_error_noise.pdf
                      Reply  Tue Dec 6 16:47:40 2016, Koji, Update, IOO, IMC WFS whitening filter investigation D990196-C.pdf
                         Reply  Tue Dec 6 17:54:08 2016, Koji, Update, IOO, IMC WFS whitening filter investigation 34.png
                            Reply  Tue Dec 6 22:41:49 2016, Koji, Update, IOO, IMC WFS whitening filter investigation 
                               Reply  Tue Dec 13 17:26:42 2016, Koji, Update, IOO, IMC WFS whitening filter investigation 
                                  Reply  Thu Dec 15 03:46:19 2016, rana, Update, IOO, IMC WFS whitening filter investigation 
Message ID: 12676     Entry time: Tue Dec 13 17:26:42 2016     In reply to: 12671     Reply to this: 12678
Author: Koji 
Type: Update 
Category: IOO 
Subject: IMC WFS whitening filter investigation 

Rana pointed out that this modification (removal of 900Ohm) leave the input impedance as low as 100Ohm.
As OP284 can drive up to 10mA, the input can span only +/-1V with some nonlinearity.

Rather than reinstalling the 900Ohms, Rana will investigate the old-days fix for the whitening filter that may involve the removal of AD602s.
Until the solution is supplied, the IMC WFS project is suspended.

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